ABB RELION REX640 Technical Manual page 1439

1MRS759142 F
Function
Phase sequence current measurement
(CSMSQI)
Phase sequence voltage measurement
(VSMSQI)
Three-phase power and energy measurement
(PEMMXU)
Power and energy calculation
The three-phase power is calculated from the selected voltage and current
measurements as described in
determines which voltage and current measurements are used.
It is also possible to use positive-sequence components for calculating the apparent
power, which makes the determination of power insensitive to any asymmetry in
currents or voltages.
Table 1360: Measured apparent power
Measurement mode setting
values
PhsA, PhsB, PhsC
Arone
Pos Seq
PhsAB
PhsBC
PhsCA
Table continues on the next page
REX640
Technical Manual
Settings
Ps Seq A deadband ,
Ng Seq A deadband ,
Zro A deadband
Ps Seq V deadband ,
Ng Seq V deadband ,
Zro V deadband
Power deadband
Table 1360
. The setting
Power calculation
* *
S U I U I U I
= ⋅ + ⋅ +
A A B B C
* *
S U I U I
AB A BC C
= ⋅ − ⋅
*
S U I
3
1 1
= ⋅ ⋅
( )
* *
S U I I
= ⋅ −
AB A B
( )
* *
S U I I
= ⋅ −
BC B C
( )
* *
S U I I
= ⋅ −
CA C A
Measurement functions
Minimum/maximum
0.04/40
0.004/4
0.01/0.1
Measurement mode
*
⋅
C
(Equation 339)
(Equation 340)
(Equation 341)
(Equation 342)
(Equation 343)
(Equation 344)
1439